Low cost/high performance blind fastener

Abstract

A blind fastener is provided comprising a core bolt comprised of a bolt shaft and a bolt head. A metal sleeve is included comprising a rigid cylindrical base and a malleable cylindrical tail, the metal sleeve is positioned around the bolt shaft with the malleable cylindrical tail in communication with the bolt head. A travel stop feature is formed on the rigid cylindrical base opposite the malleable cylindrical tail. A drive feature includes a threaded bolt section extending from a foot end of the bolt shaft and a drive nut rotatably thereto. The drive nut allows the core bolt to be pulled within the metal sleeve such that the bolt head compresses the malleable cylindrical tail to form a retention button.

1 . A blind fastener comprising: 
 a core bolt comprising a bolt shaft and a bolt head;    a metal sleeve comprising a rigid cylindrical base and a malleable cylindrical tail, said metal sleeve positioned around said bolt shaft with said malleable cylindrical tail in communication with said bolt head; and    a drive feature positioned on said bolt shaft opposite said bolt head, said drive feature allowing said core bolt to be pulled within said metal sleeve such that said bolt head compresses said malleable cylindrical tail to form a retention button.    
   
   
       2 . A blind fastener as described in  claim 1 , further comprising: 
 a travel stop feature formed on said rigid cylindrical base opposite said malleable cylindrical tail.    
   
   
       3 . A blind fastener described in  claim 2 , wherein said travel stop feature comprises an outwardly flanged feature.  
   
   
       4 . A blind fastener as described in  claim 1 , wherein said drive feature comprises: 
 a threaded bolt section extending from a foot end of said bolt shaft; and    a drive nut rotatably mounted to said threaded bolt section.    
   
   
       5 . A blind fastener as described in  claim 4 , further comprising: 
 a break-neck groove formed between said threaded bolt section and said bold shaft, said break-neck groove allowing said drive feature to be snapped off after installation.    
   
   
       6 . A blind fastener as described in  claim 1 , wherein said malleable cylindrical tail is permanently affixed to said bolt head.  
   
   
       7 . A blind fastener as described in  claim 6 , wherein said malleable cylindrical tail is permanently affixed to said bolt head by a means taken from the group of bonding, brazing, welding, spin welding, and frictional welding.  
   
   
       8 . A blind fastener as described in  claim 1 , wherein said metal sleeve comprises a sleeve outer diameter approximately equal to a bolt head outer diameter.  
   
   
       9 . A blind fastener as described in  claim 1 , wherein said malleable cylindrical tail comprises a titanium-columbium alloy.  
   
   
       10 . A blind fastener as described in  claim 5 , wherein said break-neck groove comprises: 
 a v-groove having a v-groove location and a v-groove depth configured to break upon said drive feature exceeding the force required to form said retention button.    
   
   
       11 . A blind fastener as described in  claim 4 , further comprising: 
 a wrench flat formed on said threaded bolt section.    
   
   
       12 . A blind fastener comprising: 
 a core bolt comprising a bolt shaft and a bolt head;    a metal sleeve comprising a rigid cylindrical base and a malleable cylindrical tail, said metal sleeve positioned around said bolt shaft with said malleable cylindrical tail in communication with said bolt head;    a travel stop feature formed on said rigid cylindrical base opposite said malleable cylindrical tail; and    a drive feature comprising a threaded bolt section extending from a foot end of said bolt shaft and a drive nut rotatably mounted to said threaded bolt section, said drive nut allowing said core bolt to be pulled within said metal sleeve such that said bolt head compresses said malleable cylindrical tail to form a retention button.    
   
   
       13 . A blind fastener described in  claim 12 , wherein said travel stop feature comprises an outwardly flanged feature.  
   
   
       14 . A blind fastener as described in  claim 12 , further comprising: 
 a break-neck groove formed between said threaded bolt section and said bold shaft, said break-neck groove allowing said drive feature to be snapped off after installation.    
   
   
       15 . A blind fastener as described in  claim 14 , wherein said break-neck groove comprises: 
 a v-groove having a v-groove depth configured to break upon said drive feature exceeding the force required to form said retention button.    
   
   
       16 . A blind fastener as described in  claim 14 , wherein said break-neck groove comprises: 
 a v-groove having a v-groove location configured to break upon said drive feature exceeding the force required to form said retention button.    
   
   
       17 . A blind fastener as described in  claim 12 , wherein said malleable cylindrical tail is permanently affixed to said bolt head.  
   
   
       18 . A blind fastener as described in  claim 12 , wherein said malleable cylindrical tail comprises a titanium-columbium alloy.  
   
   
       19 . A blind fastener as described in  claim 12 , wherein said malleable cylindrical tail comprises an aluminum alloy.  
   
   
       20 . A method of joining a first material to a second material using a blind fastener, the method comprising: 
 inserting a blind fastener through the first material and second material, said blind fastener comprising:    a core bolt comprising a bolt shaft and a bolt head;    a metal sleeve comprising a rigid cylindrical base and a malleable cylindrical tail, said metal sleeve positioned around said bolt shaft with said malleable cylindrical tail in communication with said bolt head;    inserting said blind fastener until a travel stop feature formed on said rigid cylindrical base opposite said malleable cylindrical tail engages said first material;    torquing a drive feature formed onto said bolt shaft, said drive feature comprising a threaded bolt section extending from a foot end of said bolt shaft and a drive nut rotatably mounted to said threaded bolt section, said drive nut pulling said core bolt within said metal sleeve such that said bolt head compresses said malleable cylindrical tail to form a retention button;    generating a compression torque securing the first material to the second material by way of pressure between said travel stop feature and said retention button.    
   
   
       21 . A method as described in  claim 20 , further comprising: 
 breaking said drive feature off of said bolt shaft after forming said retention button.    
   
   
       22 . A method as described in  claim 20 , further comprising: 
 torquing said drive feature until a v-groove breaks, said v-groove breaking upon said drive feature exceeding the force required to form said retention button.    
   
   
       23 . A method as described in  claim 21 , wherein: 
 said malleable cylindrical tail is permanently affixed to said bolt head such that said core bolt is retained within said metal sleeve after said drive feature is broken off.